The present invention relates generally to vehicle powertrain systems and, in particular, to a low noise gear pump that reduces gear wear.
Gear pumps and motors are some of the most durable pumps available. The noise that these pumps generate, however, is objectionable for many applications. Controlling this noise source is desirable. Noise level and frequency are affected by the type of gear teeth, the geometry of the gear tooth, the gear tooth surface and the lubrication. Much of the noise is generated by oil that becomes trapped between the gear teeth as they mesh.
In many instances, altering the type of gear teeth used or smoothing the tooth surface is not possible where amending the geometry of the gear tooth may compromise the gear's ability to transmit load. Further, using higher viscosity oils and greases can cut down on noise but may not be well suited for every gear unit.
It is desirable, therefore, to provide a low noise gear pump that additionally reduces gear wear.